var checkType=true;
var userNum;
while (checkType){
	userNum=prompt("Enter a value");
	if (isNaN(userNum)==false){
		checkType=false;
	}
}
for (counter=1; counter<=userNum; counter++){
	if (counter%5==0){
		document.write("<b>" + counter + "</b>" + "<br>");
		}
	else{
		document.write(counter + "<br>");
		}
}